localisation of function Flashcards
Localisation of function
Def
Consists of
Refers to the belief that specific areas of the brain are associated with specific cognitive processes
Motor cortex
Somatosensory cortex
Visual centres
Auditory centres
Language centres: brocas/wernickes
Motor cortex
A region of the brain responsible for the generation of voluntary motor movements
Located in the frontal lobe of the brain along the precentral gyrus
Both hemispheres have a motor cortex, each responsible for the opposite side of the body
Diff parts of the body are responsible for control of different parts of the body and they are arranged logically next to each other
Somatosensory cortex
A region of the brain that processes input from sensory receptors in the body that are sensitive to touch
Detects sensory events arising from different regions of the body
Located in the parietal lobe along the postcentral gyrus
Using sensory info, the somatosensory cortex produces sensation to touch, pressure, pain and temp which then localises to specific body regions
Both hemispheres have a somatosensory cortex, with the cortex on one side on the brain recieving info from the opposite side of the body
Visual centres
Primary visual centres are located in the visual cortex, in the occipital lobe
However, visual processing begins in the retina where light enters and strikjes the rods and cones
Nerve impulses from the retina are then transmitted to the brain from the optic nerve
majority terminate in the thalamus, which acts as a relay station passing info to the visual cortex
Visual cortex spans both hemispehre but right hemisphere gets info from left hand side of visual field and vice versa
Visual cortex has diff areas, each processing diff info
Auditory centres
Hearing
Most of this are lies in the temporal lobes in auditory cortex on both sides of brain
Auditory pathways begin in cochlea where sound waves are connected to nerve impulses which travel via auditory nerve to auditory cortex in brain (stop of at brain stem- decoding, thalamus- relay station and further processing, auditory cortex- sound is recognised)
Language centres
Broca’s area
Wernicke’s area
Broca’s area
An area in the frontal lobe of the brain, usually in the left hemisphere, related to speech production
- post mortem on tan
- couldnt express self in writing or speech, but could undersatnd when spoken to
Expressive aphasia
Wernicke’s area
An area in the temporal lobe of the brain important in the comprehension of language
-post mortom
- could say words which conveyed no meaning and showed no understanding when spoken to
AO3: Equipotentiality
Not all researchers agree that cog function is localised
Lashley equipotentiality theory
Basic motor and sensory functions are localised but higher ones arent
Intact areas of the cortex could take over responsibility following injury to regain some cog abilities following damage to specific areas
AO3: Aphasia studies
Evidence for Broca’s and Wernickes comes from the discovery that damage to these areas results in ephasia
Expressive aphasia- brocas aphasia- is an impaired ability to produce lang bc of damage to Bs area in most cases
Receptive aphasia - wernickes aphasia- is an impaired ability to understand language bc of damage to Ws area
Demonstrated important role played by these regions
AO3: individ diffs
Pattern of activation observed in response to various laguage activities varies from individual to individual
Research: variability in patterns of activation when reading. Right temporal lobe, left temporal, frontal and occipiatkl lobes
Gender diffs in size of areas- research found F have large Bs and Ws area
Anatomical diffs= explain superior lang skills often found in females
